Addressing delays to treatment in patients with Chronic Limb-Threatening Ischaemia

Patients with CLTI often face long delays from referral to the vascular surgery service and hospital admission to revascularisation, and there is limited evidence on the effect of these delays on patient outcomes. This thesis aims to identify factors associated with delays to treatment in patients with CLTI and explore interventions to address them.

The first cohort study estimated that only 51% of patients admitted as emergencies with CLTI have revascularisation within the recommended 5-days. Factors associated with delayed revascularisation were older age, more comorbidities, presence of infection and tissue loss, open procedures, and admission later in the week. The latter reflects how services are organised and supports arguments for 7-day vascular service. A further cohort study found that the delays from emergency admission to revascularisation were independently associated with higher 1-year mortality in patients undergoing revascularisation for CLTI with tissue loss but not in those with less severe forms of PAD, and there was no evidence of an association between delay and major amputation.

Subsequently, a Quality Improvement Collaborative (QIC) between eleven vascular centres was implemented to identify interventions that can reduce delays to revascularisation. These interventions significantly increased the proportion of patients revascularised within 5-days, and reduced the length of hospital stay and 30-day readmission rate compared to baseline performance. The reduction in LOS and readmission rate were significantly higher than in non-participating centres. A mixed methods study of semi-structured interviews and an online survey with participating clinicians identified factors that influenced the local uptake of changes and the success of this vascular QIC.

Finally, the COVID-19 pandemic was an important contextual factor during the QIC.A cohort study examining its effect found a 28% reduction in vascular lower limb activity during the COVID-19 pandemic more marked for elective revascularisation procedures, and increased mortality related to concomitant SARS-CoV-2 infection.